1. Write an example of one diatomic molecule and triatomic molecule each. 2. A pair of bullocks exerts a force of 140 Newton on a plough. The field being ploughed is 15 m long; how... 1. Write an example of one diatomic molecule and triatomic molecule each. 2. A pair of bullocks exerts a force of 140 Newton on a plough. The field being ploughed is 15 m long; how much work is done on ploughing field? 3. Draw a well labelled diagram of a neuron. 4. Write the differences between tendons and ligaments. 5. The volume of a 50 gram of a solution is 20 cm cube. If the density of water is one gram per centimete cube, then will the substance float or sink in water? 6. Hydrogen and oxygen combine in the ratio of 2:1 to form water. What mass of Oxygen gas would be required to react completely with 3 grams of hydrogen gas? 7. Calculate the molecular mass of the following: a) C6H14 b) C4H8 c) C12H6 8. Write three differences between striated its smooth and cardiac muscles. 9. Name the tissue which: a) Connects bone to bone in humans. b) A former lining of mouth. 10. A liquid connective tissue. 11. The volume of a 500 gram sealed packet is 350 cm cube. Will packet float or sink in water; if density of water is one gram per cube? What will be mass of water displaced by the packet? 12. Define Power. The power of a motor is 2 kilowatt; how much water per minute this pump can raise to a height of 10 m? (g=10 m per second squared). 13. A crane lift a crate upward through a height of 20 m, lifting force provided by train is 5 kilo Newton; how much work is done by the force? 14. Who is known as Father of Chemistry? What are the two laws of chemical combination? State giving examples of each. 15. Write the chemical formula of the following: a) Tissue found in Plants for water transport. b) Magnesium hydroxide c) Sulphur dioxide d) Calcium carbonate e) Water. 16. Aluminium chloride; 17. A force acting on a mass of 20 kg changes its velocity from 5 m per second to 7 m per second. Calculate the work done by the force. Read more

Steps to Solve

1. Identify Diatomic and Triatomic Molecules

A diatomic molecule consists of two atoms, while a triatomic molecule consists of three.

• Example of a diatomic molecule: Oxygen ($O_2$)
• Example of a triatomic molecule: Water ($H_2O$)

2. Calculate Work Done on Ploughing

Work done is calculated using the formula: $$ \text{Work} = \text{Force} \times \text{Distance} $$

Substituting the values provided: $$ \text{Work} = 140 , \text{N} \times 15 , \text{m} = 2100 , \text{J} $$

3. Draw a Neuron

Draw a well-labeled diagram of a neuron, showing the dendrites, cell body, axon, and axon terminals.

4. Differences Between Tendons and Ligaments

• Tendons connect muscles to bones.
• Ligaments connect bones to bones.
• Tendons are flexible and strong, while ligaments are slightly elastic.

5. Determine Floating or Sinking of the Substance

The density of the solution is calculated as: $$ \text{Density} = \frac{\text{Mass}}{\text{Volume}} = \frac{50 , \text{g}}{20 , \text{cm}^3} = 2.5 , \text{g/cm}^3 $$

Since density ($2.5 , \text{g/cm}^3$) is greater than the density of water ($1 , \text{g/cm}^3$), the substance will sink.

6. Calculate Mass of Oxygen Required for Reaction

Using the molar mass ratio of hydrogen and oxygen: $$ \text{H}_2 + \dfrac{1}{2}\text{O}_2 \rightarrow \text{H}_2O $$

Calculate the mass of oxygen needed for 3 grams of hydrogen:

1. Molar mass of Hydrogen = 1 g/mol, so 3 g = 3 moles of H.

2. For 2 moles of H, 1 mole of O is required, therefore for 3 moles: $$ \frac{1 , \text{mole of O}}{2 , \text{moles of H}} = \frac{3}{2} = 1.5 , \text{moles of O} $$ This equals: $$ 1.5 , \text{moles} \times 32 , \text{g/mol} = 48 , \text{g of O} $$

3. Calculate Molecular Mass

• For $C_6H_{14}$: $$ 6(12) + 14(1) = 72 + 14 = 86 , \text{g/mol} $$

• For $C_4H_8$: $$ 4(12) + 8(1) = 48 + 8 = 56 , \text{g/mol} $$

• For $C_{12}H_6$: $$ 12(12) + 6(1) = 144 + 6 = 150 , \text{g/mol} $$

8. Differentiate Muscle Types

• Striated Muscle: Voluntary, striped appearance.
• Smooth Muscle: Involuntary, non-striated.
• Cardiac Muscle: Involuntary, striated, only in the heart.

9. Name Tissues

• Connects bone to bone: Ligament.
• Former lining of mouth: Epithelial tissue.

10. Identify Liquid Connective Tissue

Blood is the liquid connective tissue.

11. Determine Float or Sink of Packet

Calculate: $$ \text{Density of Packet} = \frac{500 , \text{g}}{350 , \text{cm}^3} = 1.43 , \text{g/cm}^3 $$

Since $1.43 , \text{g/cm}^3$ is greater than $1 , \text{g/cm}^3$, it will sink. The mass of water displaced is equal to the volume of the packet: $$ 350 , \text{cm}^3 \rightarrow 350 , \text{g} $$

12. Define Power and Calculate Water Raised

Power is defined as: $$ \text{Power} = \frac{\text{Work}}{\text{Time}} $$

The work done to raise water can be calculated: $$ \text{Work} = \text{Weight} \times \text{Height} = \text{mass} \times g \times h $$

Where:

• Weight = Volume x Density, which we can calculate by the pump's rate.

13. Calculate Work Done by Crane

Using: $$ \text{Work} = \text{Force} \times \text{Distance} = 5 , \text{kN} \times 20 , \text{m} = 100 , \text{kJ} $$

14. Father of Chemistry and His Laws

• Father of Chemistry: Antoine Lavoisier.
• Two Laws:
  1. Law of Conservation of Mass - Mass is neither created nor destroyed.
  2. Law of Definite Proportions - A chemical compound always contains the same proportion of elements.

15. Chemical Formulas

• Tissue for water transport: Xylem.
• Magnesium hydroxide: $Mg(OH)_2$.
• Sulphur dioxide: $SO_2$.
• Calcium carbonate: $CaCO_3$.
• Water: $H_2O$.

16. Aluminium Chloride Formula

Aluminium chloride: $AlCl_3$.

17. Work Done by Force Calculation

Using: $$ \text{Work} = \Delta KE = \frac{1}{2} m (v_f^2 - v_i^2) $$ Where:

• $m = 20 , \text{kg}$, $v_i = 5 , \text{m/s}$, $v_f = 7 , \text{m/s}$ Calculating gives: $$ \text{Work} = \frac{1}{2} \times 20 \times (49 - 25) = 240 , \text{J} $$